Fair Value Measurements (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Real Estate Fund Nondepreciable Real Estate	$ 667,710	$ 600,786
Real Estate Fund [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Excess of fair value over cost	153,413
Unobservable Quantitative Input [Abstract]
Opening Balance - changes in Level 3 " deferred compensation plan assets"	600,786	346,650
Purchases	43,816	262,251
Sales/Returns	(70,848)	(63,762)
Net realized gains	8,184	0
Net unrealized gains	85,771	55,361
Other, Net	1	286
Closing Balance - changes in Level 3 " deferred compensation plan assets"	667,710	600,786
Real Estate Fund [Member] | Minimum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs Holding Period	0 years 7 months 6 days
Unobservable Quantitative Input [Abstract]
Discount rates	12.00%
Terminal capitalization rates	5.00%
Real Estate Fund [Member] | Maximum [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value Inputs Holding Period	6 years 6 months
Unobservable Quantitative Input [Abstract]
Discount rates	17.50%
Terminal capitalization rates	6.00%
Real Estate Fund [Member] | Weighted Average [Member]
Unobservable Quantitative Input [Abstract]
Discount rates	13.90%
Terminal capitalization rates	5.50%
Deferred Compensation Plan Assets [Member]
Unobservable Quantitative Input [Abstract]
Opening Balance - changes in Level 3 " deferred compensation plan assets"	62,631	56,221
Purchases	5,018	9,951
Sales/Returns	(7,306)	(8,367)
Realized and unrealized gains	7,189	4,703
Other, Net	1,250	123
Closing Balance - changes in Level 3 " deferred compensation plan assets"	$ 68,782	$ 62,631